Charging system for blast furnaces



Dec. 29, 1925- W. E. HARRISON ET AL CHARGING SYSTEM FOR BLAST FURNACES Filed Feb. 24, 1921 5 sheets sheet 1 glvvuwntow VVLECHar-r ison,

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W. E. HARRISON ET AL CHARGING SYSTEM FOR BLAST FURNACES Dec. 29, 1925 Filed Feb. 24, 1921 3 Sheets-Sheet WEHar-r 31402 11 You 6601p K D-Siezmrt,

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Dec. 29, 1925 1,567,642

w. E. HARRISON ET AL CHARGING SYSTEM FOR BLAST FURNACES Filed Feb. 24, 1921 5 Sheets-Sheet 3 WE Ha rrisow, III-126%; warZ',

Patented Dec. 29, 1925.

UNITED STATES PATENT OFFICE.

mm B. HARRISON AND KENNETH D. STEWART, YOUNGSTOWN, OHIO.

GHARGIII'G SYSTEM FOR BLAST FURNACES.

Application am February 24, 1921. Serial Io. 447,697.

To all whom it may concern:

Be it known that we, WILLIAM E. Hnmu- SON and KENNETH D. STEWART, citizens of the United States, residing at Youngstown in the county of Mahonmg and State of Ohio, have invented certain new and useful Improvements in Char in Systems for Blast Furnaces, of whic t e following is a specification.

This invention relates to a novel charging system for blast furnaces and possesses s ecial utility in roviding for returning no dust to the urnace at a point below the regular charge of constituent elements in process of reduction, in such manner that it will mingle directly with the molten metal at the bottom of the furnace.

Accordingly a primar object of the invention is to provide a last furnace wi h an equi ment which may be employed economical and in a practical manner to very efiz'ectualfy utilize the downcomer or flue dust resulting from the operation of blast furnaces, also to provide an equipment of that kind which is available as a charging system to inject other ingredients, when desired or required, into the furnace, through or adjacent the blow pipes or tuyeres.

As is well known by those familiar with the operation of blast furnaces, the various substances entering into the composition of iron are introduced into the furnace stack at the top, and are held in suspension by the hot blast (hot air introduced into the furnace near its lower end) aided by the inwardly inclining furnace well until they reach the molten stage, and in this molten condition the metal drops down, against this air pressure, to the bottom of the furnace stack. I

During this process, large uantities of the finer ortions or particles 0 the ingredicuts are blown upwardly in the stack, and escape through pipes known as downcomers, in the form known as flue-dust. This flue-dust is heavily laden with pure iron, estimated between and and the loss of this, of course, results in a very heavy economic waste. Under the present methods of operation, this dust is sometimes taken to a sintermg plant where it is resintered, and then a sin introduced into the furnace with 01; or material. This,

however, is an expensive operation, and even at that, mevitab y results in more or less loss or waste of iron.

As stated above, the our invention is to rovi this flue-dust may returned to the furnace stack in dust form in such manner that instead of mixing with the regular unreduced charge at the top, it will immediately minfile with the already molten metal at the ottom of the furnace, so that practically the entire percentage of the iron therein will be recovered.

While the (primary object of this invention, as state above, is the return of fluedust to the furnace stack, it ma also be used with great advantage when esired to inject an a ditional portion of some certain constituent element which enters into the composition of iron. For instance, if the iron, in its molten condition, indicates too high a degree of silicon it becomes necessary to introduce an additional amount of lime, which may be injected by means of our invention, in such manner as to bring it into immediate contact with the molten mass at the bottom of the furnace stack. Or, if too low in sllicon, too much lime, it becomes necessary to introduce dolomite, or other ingredients. If too high in sulphur, coke is introduced in the same manner.

Again, if the furnace is working limey, using trade parlance, it is often necessary to introduce a charge of sand, which is now done from the top, requiring twelve or fourteen hours to work its way through the charge in the furnace, whereas, with our invention this sand may be introduced beneath the regular furnace charge, thus producing almost immediate results in the chan e of the condition of the furnace. Should the furnace get cool, requiring an additional amount of coke, this may be immediately introduced below the charge in contact with the hot blast, and immediate results obtained.

With these and other objects in view, as the nature of the invention is better understood, the same consists in the novel construction, combination and arrangements of parts hereinafter more fully illustrated, described and claimed.

The primary features of the invention are rimary object of e means by which susceptible of a variety of structural changes and mfidifications, but preferred and practical forms of the invention are shown in the accompanying drawings, in which Figure 1 is a iagrammatic plan view of the eneral arrangement of the invention in com ination with the stoves and furnace.

Figure 2 is a diagrammatic side elevation of the arran ement shown in Figure 1.

Fi ure 3 1s a vertical sectional view of the ower end of the furnace illustrating one means for introducing the dust charge into the furnace.

Fi re 4 is an enlarged detail vertical sectiona view taken on the line 44 of Fig. 1 showing the valve in the cold air blast line.

Figure 5 is a detail vertical sectional view of the charge receiver illustrating the agitating means therein.

Figure 6 is a more or less diagrammatic horizontal sectional view of a furnace showing a modified arrangement for introducing the charge into the furnace.

Similar reference numerals designate corresponding arts throughout the several figures of the drawings.

The general construction of a blast furnace includes a cold air pipe A, leading from the blowing engine to the heating stoves B into which the air passes, and from which it is discharged in its heated state through the supply pi e C to the bustle pipe D surrounding the urnace stack E at a point well below the lon itudinal or vertical center of the stack. ommunicating with the bustle pipe D are a plurality of blowipes F, the inner ends of which enter the urnace stack wall, and communicate with the furnace interior through the usual tuyeres and through these blow pipes the hot air passes from the bustle pipe into the furnace stack. This is known as the hot-blast.

The usual blast furnace equipment ordinarily includes means for heating the cold air before it is discharged into the furnace through the blow pipes and tuyeres. Certain parts of said air supplying and air controlling means are utilized for the purposes of the present invention and referrin thereto, the cold air ipe A has include therein a valve casin (5 in which is mounted a butterfly valve H aving a rod or equivalent operating connection I with a piston valve J which slidably fits within a ported valve cage K surmounting the valve casing G and in communication with the same and the air pipe A through the open throat L. The shell or wall of the said valve cage K is provided with a plurality of air ports M which are controlled and regulated by the iston valve J, the operatin rod or stem of which is so connected wit the butterfly valve H that when the latter is open for the passage of air into the heating stoves the piston is automatically drawn to its lower position coverin or closin the air orts.

Conversely, w en the va vs 1-]? is c osed against assage of the air into the heatin stoves, t e piston is automatically forced upwardly uncovering the air ports. This apparatus is known in furnace practice as a snort valve and Fi 4 of the drawing illustrates a standard orm thereof.

The present invention proposes to utilize the air discharged throu h the uncovered air ports and tothat end provides the receiving chamber N which is in the form of a hood surrounding the valve cage K and providing a coupling between the air pressure supply pipe 1, of the present char ing system, and the cold air blast pipe A o the usual equi ment. Adjacent the receiving chamber for the cold air blast, the air pressure sup ly pipe 1 is preferably fitted with a suita le controlling valve 2 and at a point beyond the said controlling valve has fitted therein an automatic relief valve 3 of any suitable type which may be adjusted or set to operate according to an predetermined pressure. Furthermore, t e air pressure supply pipe 1 has connected therewith between the valves 2 and 3 one end of a by-pass 4 provided with a suitable controlling valve 5 therein and whose other end is connected as at 6 with the cold air blast pipe A at a point between the butterfly valve and the source of air su ply so that air pressure is available from e blast ipe A at all times regardless of whether the utterfly valve H is open or closed.

The air pressure supplying means described which includes t e pipe 1 and its connections respectively with the butterfly valve controlling device, and with the valved by-pass 4, is associated with the feeding means which supply the flue-dust, or other elements to the delivery pipe 7, which delivers the said flue-dust or other elements to an annular distributing pipe surrounding the blast furnace below the bustle pipe D and which distributing pi e is provided with a plurality of valved c arging nozzles 9, each of which nozzles referably is connected as at 10 with one of the blow pipes F of the hot blast so that the flue-dust or other elements may be introduced into the furnace directly through the blow-pipe.

The feeding means referred to, therefore, is operated in conjunction with the air pressure supplying means and in turn provides the supp y or charge which is to be forcibly delivered through the delivery pipe 7. The said feeding means may be of any suitable construction or character according to the purpose intended, but for illustrative purposes, there is shown in the drawings one type which may be resorted to: T1118 primaril includes a charge receiver 11 which may e said to be introduced into the air pomssure line and is in communication with th the source of feed as well as with the delivery pipe 7. The said charge receiver top of the receiver 11 through a valved feed y a measurin connection 13 which in turn may communicate with the bottom of what may be termed a feeder drum 14 havin a valved pressure pipe connection 15 wit the air pressure supply pipe 1 and an adjustable relief valve 16 connected with the top part thereof. sup 1y of the flue-dust or other substance is re erably measured into the said drum 14 scale 17 (diagrammatically indicated), an the said scale is fed by a supply hopper 18, in turn being charged with the flue-dust or other substance by a feeding device 19 which may consist of a bucket elevator or e uivalent mechanism. In the operation of t e feeding means, flue-dust or other substance may be allowed to freely run from the supply hopper 18 directly into the char e receiver 11 and there picked up by the last of air and blown through the delivery pipe 7, the distributing pipe 8 and the charge nozzles 9 into the urnace. In cases where a mixture is employed, or there is a tendency to cake or 010 the air pressure pipe 15 serves to brea that up and forcib y feed the charge receiver 11, and in the event of the valved connection 13 being throttled, the relief valve 16 will relieve back ressure in the drum.

A. modi cation of the invention is suggested in Figure 6 of the drawings, wherein the charging nozzles 9 of the distr'buting pipe 8 are shown disassociated from he hot blast pipes of the furnace and enter the furnace through separate apertures, but within the circular plane, or adjacent the circular plane, of the said hot blast pipes.

It should be noted that the ordinary equipment for a blast furnace as hereinbefore referred to, includes the cold air blast pipe leading to the heating stoves and it also includes the butterfly valve, the valve cage K and the piston J, the said valve device ordinarily being used to permit air to escape to the atmosphere when the butterfly valve cuts ofl the supply of cold air to the stoves. However, as that operation would be liable to reduce the pressure in the by-pass pipe 4 to too low a point, the receiving chamber N is placed about the said including a col cage K so that the air which ordinarily escapes to the atmos here at that point is trapped and directe into the air pressure supply pipe 1 should it be desired to augment the ressure obtained through the bypass 4. n connection with this part of the apparatus, the receiving chamber N may be provided with an adjustable relief valve 20 of any suitable and approved type.

From the foregoing, it is thought that the construction, operation and advantages of the hereinbefore described system will now be a parent to those skilled in the art, and it wi also be understood that changes in the form, proportion and minor details of of onstruction may be resorted to without dea rting from the spirit of the invention or the pa of the appended claims.

e c aim:

1 A chargin system for blast furnaces inc uding a col air blast pipe for the furnace, a delivery pipe having communication with the furnace interior at the plane of or adjacent the hot blast, a receiver for the charge iicil communication with gaid deligery ipe, an an air ressure su 1 e avihg valved commlihioation witli t hg gold air blast pipe for the furnace.

2. A chargin system for blast furnaces including a col air blast pipe for the furnace, a delivery pipe having communication with the furnace interior at the plane of or adjacent the hot blast, a receiver for the charge in communication with said dolivery ipe, an air pressure supply pipe having va ved communication with the cold air blast pipe for the furnace, and also having aby-pass connection with said cold air blast pipe.

3. A. chargin system for blast furnaces air blast pipe leading to the air heating stoves and having a cut oil valve, a delivery pipe having communication with the furnace at or adjacent the hot blast, a receiver for the charge in communication with said delivery pipe, an air outlet valve on the cold air blast pi e havin an operating connection with said out 0 valve, and an air pressure supply pipe having its receiving end in communication with the dischar e from said air outlet valve of the cold air b ast ipe.

4. A c arging1 system for blast furnaces including a col air blast pipe leading to the air heating stoves and having a cut ofi valve, a delivery pipe havmg communication with the furnace at or adjacent the hot blast, a receiver for the charge in communication with said delivery pipe, an air outlet valve on the cold air blast pipe havin an operating connection with said cut 05 valve, and an air pressure supply pipe having its receivin end fitted with a drum communicating wit the discharge from said air outlet valve.

5. A charging system for blast furnaces including in combination, the air supply line for the furnace, a valved outlet positioned in said air supply line, a charging line communicating with the furnace at or adjacent the plane of the hot blast and communicating with the outlet valve of the said air supply line, and means for feeding a charge to said char 'ng line.

6. A c arging stem for blast furnaces includin in combination, a main air supply line for the furnace, a combination valve and outlet positioned in said main air supply line, a charging line communicating with the furnace at or adjacent the plane of the hot blast and communicating with the outlet valve of the air supply line, and means for feeding a charge to said charging line.

7. A charging system for blast furnaces includin in combination, the main air supply line %or the furnace, at snort valve in said main air suppl line, a charging line communicating wit the furnace at or adjacent the plane of the hot blast and communicating with the outlet of said snort valve, and

ineans for feeding a charge to said charging 8. A charging system for blast furnaces including in combination, the main air supply line for the furnace, a snort valve in said main air supply line, a charging line communicating with the furnace at or adjacent the plane of the hot blast, and means connecting the outlet of said snort valve with said charging line.

9. A charging system for blast furnaces includin in combination, the main air supply line or the furnace communicating with the tuyeres, a charging line communicating with the furnace at or adjacent the plane of the hot blast and means located in said main air supply line for intercepting the current of air passing therethrough and diverting i portion of the same through said charging In testimony whereof we hereunto aflix our signatures.

WILLIAM E. HARRISON. KENNETH 1). STEWART.

5. A charging system for blast furnaces including in combination, the air supply line for the furnace, a valved outlet positioned in said air supply line, a charging line communicating with the furnace at or adjacent the plane of the hot blast and communicating with the outlet valve of the said air supply line, and means for feeding a charge to said charging line.

6. A charging system for blast furnaces including in combination, a main air supply line for the furnace, a combination valve and outlet positioned in said main air suply line, a charging line communicating with the furnace at or adjacent the plane of the hot blast and communicating with the outlet valve of the air supply line, and means for feeding a charge to said charging line.

7. A charging system for blast furnaces includin in combination, the main air supply line for the furnace, at snort valve in said main air suppl line, a charglng line comniunicating wit the furnace at or adjacent the plane of the hot blast and communicating with the outlet of said snort valve, and

ineans for feeding a charge to said charging 8. A charging system for blast furnaces including in combination, the main air supply line for the furnace, a snort valve in said main air supply line, a charging line communicating with the furnace at or adjacent the plane of the hot blast, and means connecting the outlet of said snort valve with said charging line.

9. A charging system for blast furnaces including in combination, the main air supply line for the furnace communicating with the tuyeres, a charging line communicating with the furnace at or adjacent the plane of the hot blast and means located in said main air supply line for intercepting the current of air passing therethrough and diverting i portion of the same through said charging In testimony whereof we hereunto afiix our signatures.

WILLIAM E. HARRISON. KENNETH D. STEWART.

Certificate of Correction.

It is hereby certified that Letters Patent 'No. 1,567,642, granted December 29 1925, upon the application of William E.

Harrison and Kenneth 1). Stewart, 0%

Youngstown, Ohio, for an im rovement in Char ing Systems for Blast Furnaces,

were erroneously issued to t e inventors, said rrison and Stewart, whereas said Letters Patent should have been issued to W. E. Harrison, said Harrison being assignee of the entire interest 1n said invention, as shown by the record of assi ments in this oflioe; and that the said Letters Patent should have been read with this correction therein that the same may conform to the record of the Patent Oflice.

case in the Signed and sealed. this 23d day of February, A. D. 1926.

WM. A. KINNAN,

Actmg Oommiuioner of Patmtu Certificate of Correction.

It is hereby certified that Letters Patent No. 1,567,642, granted Deoember 29, 1925, upon the application of William E. Harrison and Kenneth D. Stewart, of Youngstown, Ohio, for an improvement in Char 'ng Systems for Blast Furnaces," were erroneously issued to the inventors, said rrison and Stewart, whereas said Letters Patent should have been issued to W. E. Harrison, said Harrison being assignee of the entire interest in said. invention, as shown by the record of assignments in this ofiioe; and that the said Letters Patent should have been read with this correction therein that the same may conform to the record of the case in the Patent Ofiioe.

Signed and sealed this 23d day of February, A. D. 1926.

[HEAL] WM. A. KINNAN,

Acting Gommiuioner of Patents: 

